The Capitol Police and Florida law enforcement are investigating a threat against Sen. Marco Rubio (R-Fla.).

Capitol Polices spokeswoman Lt. Kimberly Schneider told Roll Call that &ldquo;we are working with local law enforcement in Miami,&rdquo; where Rubio has a home.

&ldquo;USCP currently has an active opening investigation re: the report of a threat against Sen. Rubio,&rdquo; Schneider continued in an emailed statement.

The Miami Herald first reported that Rubio had been threatened, but no information has been provided as to the nature of the threat and the extent to which Rubio is receiving additional security protection.

The Herald reported Tuesday evening that a &ldquo;uniformed cruiser&rdquo; was parked outside Rubio&rsquo;s Miami residence and that he was &ldquo;likely&rdquo; to have security &ldquo;with or near him&rdquo; during his visit to the Brookings Institution today.

Schneider would not confirm what steps are being taken to make sure Rubio has adequate protection, saying simply that &ldquo;we don&rsquo;t discuss the security of Members of Congress.&rdquo;

There have been a number of threats made against lawmakers over the past several months, including a rash of threatening letters and &ldquo;suspicious powder&rdquo; mailed to most Senators at their state and Capitol Hill offices. The substances all turned out to be harmless and an individual in the Pacific Northwest was apprehended.

Individual lawmakers have also been targets during the past several months in isolated incidents, including Rep. Bobby Schilling (R-Ill.) and House Majority Leader Eric Cantor (R-Va.).

Rubio spokesman Alex Burgos said the office was referring all inquiries on the matter to the Capitol Police and would not comment on the incident.